Electromagnetic trip circuit breaker



Dec. 22, 1953 J. B. MaGNElLL ET AL ELECTROMAGNEIIC TRIP CIRCUIT BREAKERFiled July 22, 195o 4 Sheets-Sheet l John B. MocNeiH 8 Hurry J. Lingul,BY/

ATTbRNE Dec. 22, 1953 J. B. MaoNElLL ET AL 2,663,774

ELECTROMAGNETIC TRIP CIRCUIT BREAKER Filed July 22, 1950 4 Sheets-Shea?l2 WITNESSES: {NVENTORS John BA MocNeill 8\ Hurry J. Lingul.

xi" TORNEY d Dec. 22, 1953 J. B. MaCNElLL ET AL ELECTROMAGNETIC TRIPCIRCUIT BREAKER Filed July 22, 1950 4 Sheets-Sheet 3 2o? 2es '7' 297 2|5|99 '7| 2|9 205 3||- |95 |97 3131 i 22| 20| os 225 Flg. 5. 30| 223F|g-6- .WTNESSES: INVENTORS John B4 MocNeH 8| Harry d. Lingul. mg um!ATTORNE J. B. MaCNEILL ET AL 2,663,774 ELECTROMAGNETIC TRIP CIRCUITBREAKER 4 SI'Ieecs-Sheel 4 S R m .0,205 E .WEF O 3 1 O 0 2 T. 5 6 3 wl 6.o 2 I N .b I 6 W f f 7 1 I |1l l|| II.. I. |.I I 6 o m l f w g 9 v 3| s.cn m y e 2 2 99 H l e 0 m l I 2 2 22.7 n .I 6 V. e T .T 9 2 9 l S D f 2O n S O l f2 .W e e U O $5 7 d m m w I O RDV W. A n xnlv W 2 2 V. .u I.Mw I U .m s 3 9 9 n l 1 n n n 5 lh 2 2 I e S S O 3 n 4 5 5 3 m I 7. l 42 3 Q H V 2 3 3 m T .m .T H 3 m. 0 5 7 O R 208 7. 3 4 L .1.V..4|22 5 7 22 O m .m mm 8 2 O .n.le 2 0C S TD 0 7 f O w 0 D. E u w 4 6 7 5 U .m 5 5Oe h Ti 2 2 D. k O C S D. 000009 U .mw 4r 80246 P e P 46789 k P 7 snoicmwm u D Pn we I T.| 7 e m P 33 3 g w1 em 3 I B ekn ml 3 F mC@ .IS.Til 02468n|v I TU nd gev. 5 Dim .la o nmmnIhIF.. T m nd mA -o um @www yw A www mA m s 0 O 0 O M O e d S .l l W 6 7 8 9 2 LD A N I 7 P 2 O O O OO O0 O 0 64 2 I 64 2 I 64 2 l W 4 0 2 O Mw w m 0 64 2 l O0. O 0 I Dec.22, 1953 Filed July 22, 195o m-UCCOww E @E F.

TTORNEY Fig.9.

4valve means to admit Patented Dec. 22, 1953 UNITED STATES PATENT OFFICEELECTROMAGNETIC TRIP CIRCUIT BREAKER John B. MacNeill and Harry J.Lingal, Pittsburgh,

Pa., assignors to Westinghouse Electric Corporation, East Pittsburgh,Pa., a corporation of Pennsylvania f Application July 22, 1950, SerialNo. 175,373

rents above said. predetermined valueor short cirmiits.Y i A `Another'object of the invention is to providea circuit breaker having av tripdevice einbodying a time-delay device of the uid dashpot Vtype in whichtime delays or" different duration are effected in the operation ol theVtrip device'in different ranges oi overload"currents by admitting iuiolto the dashpot at different rates. Another object oi the invention is toprovide a circuit breaker having electroresponsivetrip device embodyinga novel tiinedelay device oi the iuid dashpot type in which time delays'of dii'ierent `durations are effected inY the operation of the tripdevice b the operation of a single valve means to admit :luid to thedashpot at different rates. H

A further object of inve onis to provide 'reuit breaker having anelectroresponsivetrip device embodying a novel Vtirne-delay device' of'the luid dashpot type in which time delays o different durations areeected in the operation oi the trip device by the operation of a singletothe dashpot at different rates, the vaive ineans being selectivelyoperated eieotroinagnetically in response to overload currents ofdifferent magnitudes.

Another object oi the invention is to provide a circuit breaker with anelectroresponsive'trip device embodying a novel ine-delay means of thefluid dashpot type in which time delays of different durations areeffected in theoperation of the trip device.A by the operation of asingle valve ineens to admit fluid to the dashpotat different the valvesans being operative by a. plurality of armatures seiectively responsiveto overload currents o different magnitudes.

The novei features that are considered characteristic of the inventionare set forth in the appended claims. The invention itself, however,both as to structure and. operation, together with additional andadvantages thereof, will be best understood from the following detailedresponse to overload currents of yintermediate value below apredetermined value and instantaneously in response to overload eur- -19Claims. (Cl. ZOO-408) -cured'to a metal supporti pivotally mounted Toymeans oi' a pivot pin on e 2 description oi' a preferred einbodiiae -ttlereoi, when read in connection with the accompanying drawings.

In said drawings:

iiguie l is an elevational View', pa tion, of a circuit breakerembodying of the invention;

Fig. 2 is an enlarc'en sectional view tai; stantiallv along th .av inseothe principles is a sectional plan view evice taken substantie. ly

oi tlie timealong lin 3 and looking in the direction i c. arrows;

ri 5 is an elevational seeti vie taken substantially along line "iT-V ors, e, ng

in the direction oi' the and snowing the adjusting means for theshort-tiinedelay ar1nature;

Fig. 6 is an elevational sectional substantially on line Vl-V oi' eig.e, looking in the direction of the "ows and @lowing the control valvefor the time-delay device together with the adjusting means therefor;Fig. 7 is an elevational view oi tile time-delay device showing' thescale plate and. the several adjusting knobs;

Fig. 8 is a schematic vieiv of the trip :levi-2e illustrating theseveral adjusting ineens for tne tiineudelay device; and

."ig. 9 is a schematic diagram of adjustment oi' the trip dev' Referringto Fig. i of the breaker includes a plarolity o comprising a Contact sAvu orally at Ii and an ove cated generally at i3. Contact structure andthe trip device for each pole unit are nico-,nf a separate insulatingbase which i' view taken showing the range ig's, trie cir-cuit i ooleunits each o pole units are alike, only l y pole nin is illustrated `anddescribed The Contact structure if' n main and aroing contacts it andiii botlisecni on the inner end of a terminal conducting 23 andcooperating movable main and arci` g contacts 25 and The movablecontacts rigidly secured to a contact-carrying member U-shapecl switcharm which, in turn, is pivotally supported by pivot means 35 on brackets3l rigidly mounted on the insulating base i5.

The movable contact-carrying member 29 is electrically connected bymeans oi a fiexibie conductor 39 to the energizing coil of the tripdevice i3. A spring il compressed between the movable contact-carryingmember 29 below its pivot El and the insulating base iii providescontact pre. sure in the closed position of the breaker and also biasesthe movable contact structure in opening direction. i

The movable Contact structure is normally maintained in the closedposition by means of an operating mechanism indicated generally at 1.3mounted in a U-shaped frame The frame l5 is supported on a platform i?which forms a cross member of a generally U-shaped main bracket comrising a pair of spaced side membersv member 81 on a channel-shapedlatch 59 pivot-ed on a pivot pin Sl in the frame d5. A spring 9E servesto bias the latch lever 8l and the latch 89 to their latching positions.

A trip bar 95, extending across all of the poles of the breaker, isrigidlymounted on the righthand end of the channel-shaped latch hasinsulating brackets el (only one being shown) secured thereto, therebeing a bracket el for eacipole of the breaker. Each of the brackets u?has a headed screw 9s adiustably mounted thereon for cooperating withthe trip device i3 of its associated pole in a manner to be presentlydescribed.

mounted in the front piece of the frame de. The

49 rigidly connected at their outer ends by .the Y I cross member orplatform ell. rhe platform l extends substantially across the width oithe breaker and the side members 13E are suitably secured to the metalpanel l'a' on the outside oi the two outer pole units or" the breaker.

The operating mechanism includes a lever 5i mounted on a pivot pin esmembers of the frame The lever 5l carries a rod 55 extending across allof the poles of the breaker and is connected by means of insulatingconnecting members 5l to the pivot pins 3i the free ends of the switcharms 9, for the several poles of the breaker so that upon operation orthe rod 55 the movable contacts or" all of the poles move in unison.

An operating linkage comprising toggle links 5S, Si and G3 is providedto releasably hold the lever 5i and consequently the movable contacts inthe closed position and to operate the movable contacts to open andclosed positions. The toggle link 59 is pivotally connected to the lever5l by means of a pivot pin 65 and the toggle link 63 is pivoted on aixed pivot i?? supported in the frame Ll'i. rhe toggle link @l ispivotally conn nected to the links E15 and respectively, by knee pivotpins 59 and l'i.

The linkage 5G, 5i, comprises two toggles, one or which eil-bi bedesignated as the tripping toggle and the other t i-'s as the closingtoggle. The tripping toggle E3B-5i is normally slightly underset aboveay line drawn through the centers of the pivot pins -i and the closingtoggle iii-53 is normally underset below a line drawn through thecenters of pivot pins Sl-ES. The closing toggle 'S iis normallyprevented from collapsing downward by a support member is pivotedon apivot pin 'E5 supported in the frame d5 and having a shouldered portionengaging under the knee pivot pin li.

The tripping toggle S-Si is normally biased in a direction to cause itscollapse by a component of the force oi the springs fi-l which bias themovable contact structures for the three poles of the breaker in openingdirection and bias the connecting member 5l toward the left (Fig. l).The tripping toggle iis-Gl is normally prevented from collapsing bymeans of a main latch member Vi pivoted on the pin e.; connected bymeans of a link 'i9 to the knee pin $59 of the tripping toggle.

The main latch member 'il is held in latching position by anintermediate latch lever si pivoted on the pin l5. The intermediatelatch lever 8| carries at its upper end a latch roller E3 engaging themain latch 'il and at its lower end has a latching portion Se normallyengaging a latch supported in the handle is not shown in the drawingsbut is rigidly secured to the outer end of the sha-it le?, and biased inboth directions to a central position in a well-known manner by means oia spring I'i.

Rotation of the handle shaft m3 in tripping direction causes the cammember le! to engage and actuate the latch member 89 in counterclock-Wise or unlatching direction to unlatch the intenmediate latch levcr El,which, in turn, releases the main latch il. This permits the trippingtoggle FaS-l to collapse upwardly to eect opening of the breakercontacts. During the collapse of the tripping toggle, a portion |69 ofthe toggle link 8| engages and actuates the support member i3 to anon-supporting position, thereby freeing the closing toggle iii-$35. Theclosing toggle thereupon collapses downwardly and during its collapseresets and relatches the tripping toggle bil- El.

The breaker contacts may now be operated to the closed position byrotating the shaft its and the cam IEM in the direction opposite to thetripping direction. This causes the cam ll to engage a projection i i ion the closing toggle link 53 and moves this link counterclockwise aboutits pivot el until the support member 'i3 resumes its supportingposition below the knee pivot pin ll. During the closing operation, thelink 'i9 prevents collapse of the tripping toggle e-Si which acts as athrust transmitting means and moves the movable contact structure to theclosed position.

The breaker is automatically tripped open by operation of the tripdevice i3 for any pole of the breaker. The trip device includesgenerally a tripping electromagnet H3 (Figs. 1 and 3) and a time-delaydevice IE5. The tripping magnet H3 includes a C-shaped magnet yoke H7.The ends 23 of the magnet yoke form mounting feet and are `drilled andtapped to receive mounting bolts 25 and I2? as shown in Fig. l.

The upper end of a stationary magnet core 129 (Fig. 3) is provided withan internal "bread which cooperates with a threaded nipple 431i disposedin an opening in the magnet yoke to rigidly secure the stationary core29 to the magnet yoke.

Surrounding the stationary core member ll is an insulating tube E38around which is disposed the energizing coil lill of the magnet.

As shown in Fig. l, the bolt 25 which secures the upper end of themagnet yoke to the base i5 also secures the flexible conductor 3e to theupper turn of the coil l. The lower turn of the coil lill is formed intoa lug iii-3 which, together with the inner end lli5 of a terminal IM, issecured to the base l5 by means of a bolt leg- A tubular member l5!(Fig. 3) of magnetic material is mounted in an opening in the lowerportion of the magnetic yoke i1 'l and extends upwardly within theinsulating tube i3d. Disposed within the tubular member 151 is a movablecore member or armature indicated generally at 153 comprisino an upperportion 155 and a tubular lower portion i5?. The armature |53 isprovided with a central opening through which extends a trip rod itiextending axially through the movable armature an opening in thestationary core member and an opening in the nipple 131. A spring E53coiled about the trip rod 151 is compressed between a counterbore in thearmature 53 and a collar 55S which bears against a spring clip ideseated in an annular groove in the trip rod itl.

The trip rod |61 is moved upwardly to trip the breaker under the controlof the time-delay device li which comprises, generally, a movableabutment or iieXible diaphragm I'l (Fig. 3) cooperating with the lowerond of the trip rod and a valve element for admitting to the space belowthe movable abutment or diaphragm at various rates to provide diierentamounts of time delay. The flexible diaphragm is disposed in a chamberformed in an upper housing member 1'!! and a lower housing member 113,bother said housing members being formed of molded insui e material.rEhe outer edge of the diaphragm together with a sealing gasket isclamped between the housing members to form an air- *i t seal. Thehousing members lit-|73 are .sc-cured together rigidly secured to themagyoke l l'i by means of bolts (not shown). The central portion oi thediaphragm iii? is clamped between upper and lower clamp members 1lb andii, respectively, the upper clamp 1i9 having an annular projection 53extending downwardly through an opening in the lower clamp |31 andformed over against the lower face of the latter to form an airtightseal.

Secured to the lower end of the trip rod 16| is a sleeve l' providedwith a flange 85 to the upper face of which is suitably attached afacing 239 of a tough resilient material. The sleeve |85 is disposed ina central opening |853 in the upper clamp member H9. An annular valveseat |92 ormed on the clamp member 119 about the openrg is provided tocooperate with the facing to close the opening 18|) upon upward ortripping movement of the trip rod |1. The lower portion lidi of themovable armature extends downwardly through opening in the upper wall ofthe housing member 1l1 and is normally seated on the upper face of theupper clamp member lli? surrounding the opening |90.

Disposed in the space above the diaphragm 161 is a ring Stb having aninwardly extending flange Disposed between the flange 19". and the upperwail its of the housing member Ill is a iilter 2&1 for ltering any airthat may be drawn into the chamber through an opening 2553 (Fig. (i)formed in the wall 1529 of Ithe housing. Ordinarily in the operation orthe time-delay device, air is merely transferred from the space abovethe diaphragm to the space below the diaphragm. However, due tovariations in temperature of the surrounding atmosphere, the device maybreathe air onto and out of the chamber. The lter ttl is provided toprevent foreign matter from being drawn into the chamber by suchbreathing Since the spaces above and below the diaphragrn lo? are sealedoir` from each other and the space above the diaphragm is at atmospherlcpressure, any force tending to raise the trip rod |51 will be restrainedby the partial vacuum be low the diaphragm. In order to control the rateof tripping movement of the trip rod 16 l, a single valve deviceindicated generally at 285 (Fig. 6) is provided to admit air to thespace below the diaphragm le? at varying rates to provide long timedelay and short time delay in the tripping movement of the trip rod andalso substantially instantaneous tripping movement of the trip rod 16|.

.The valve device 205 (Fig. 6) includes a valve member 2o? having atapered valve 2de at the lower end thereoic cooperating with a taperedvalve seat 211 formed in the housing member 1li. The valve member 29'.'is disposed for sliding movementu in a metal thimble inserted in anopening 2 1 in the housing member 111 and having an enlarged portion 21?threadedly engaging the housing member. A spring 219 compressed betweenthe valve 239 and thebottomof the thimble 253 biases the valve inclosing direction. A passage in the housing member 171 communicates thespace above the diaphragm 151 to the opening 215 above the valve 289,and a passage 222 communicates the space below the diaphragm to thespace below the valve 209. Thus, the valve 2de-11 controls the passages221--223 which communicate the spaces above and below the diaphragm 1b?.Openings 225 (only one being shown) are provided in the ring 95 topermit fiow of air from the space inside the ring to the passage 221,the cross-sectional area of the openings 225 being at least equal to thecross-sectional area of the passages 221-223 at the narrowest point.

On long-time-delay tripping operations, in respense to low overloadcurrents, the valve member is not moved but is normally maintained inslightly opened position by an adjusting device (to be described later)to admit air below the diaphragm for controlling the rate or trippingmovement of the trip rod 1i`i1 on such operation. Upon the occurrence ofan overload current in the higher range of overload currents below apredetermined value, the valve 291 is opened a predetermined amount bymeans of a secondary or short-time-delay armature 221 (Figs. 4 and 5).On overload current above the predetermined value or on short circuitcurrents an instantaneous armature 225i (Figs. i and 5) is actuated tomove the valve 2t? to its full open position to permit substantiallyinstantaneous tripping movement of the trip rod Iel.

The short-time-delay armature 22? is pivotally supported at itsright-hand end (Figs. 4 and 5) by means of projections 234 which t inopenings in the right-hand wall or the housing member i. Theinstantaneous armature 22:5 is similarly supported by projection 33thereon.

The armature 229 (Figs. 2 and Ll) is biased to unattraot-ed position bymeans of a spring 235 having one end attached to the armature and theother end attached to an adjustable member 23'! threadedly engaging anadjusting screw The member 2s? is provided with a narrow pointer 2LHwhich projects through a vertical slot 243 in a scale plate 245 (seealso Fig. '7). The adjusting screw 239 suitably secured to an adjustingknob 247 (Figs. 2 and '7) journaled in an opening in the housing memberH3. Rotation of the knob 247 and the screw 239 moves the member 23? upor down, depending on the direction of rotation of the knob, and variesthe tension of the spring 235. This varies the pick-up point, that is,the minimum value of the overload current required to operate thearmature 229.

A similar adjustment is provided for the shorttime-delay armature 221(Figs. Vl and 5). A spring 2tlg, one end of which is attached to thearmature 221, has its other end attached to an adjustable member 25l(Fig. 4) similar to the menber v231. The member 25I threadedly engagesan adjusting screw 253 journaled in an opening in the housing member H3and is provided with a knob 255 (Fig. 7) for rotating the screw. Themember 25i is also provided with va pointer 251 which projects through avertical slot 259 in the scale plate 265. Rotation of the screw 253 willmove the member25l up ordown, depending on the direction of rotation, tovary the minimum overload current requiredto `actuate theshort-time-delay armature 221.

An opening 25! (Fig. 3) in the magnet yoke i I1 provides an air gap forthe magnetic circuit through the armature 229, and a similar opening(not shown) provides an air gap for the magnetic circuit through thearmature 221. As shown in Fig. each oi the armatures 221 and 229 isprovided with a recess 253, and each armature is adapted to engage undera head 255 on the upper end of the valve member 251 upon actuation ofthe armatures to effect opening movement ofthe valve member 251 andopening of the valve 259- 2ll (ig. 6). This opens the previouslydescribed communication 22 4 223 (Fig. 6) and permits air to pass fromthe space above the dia'- phragm 51 to the space below the diaphragm tocontrol the tripping movement of the trip rod i5 I. The rate oi iiow oiair to the space below the diaphragm and consequently the rate oftripping movement o the trip rod is controlled by the amount of openingoi the valve Z55-2i I.

The extent of opening movement of the valve member .251 is adjustablycontrolled by means of an S-shaped stop member 261 (Figs. 4 and 5) tothereby determine the amount of time delay provided on short-time-delaytripping operations. The upper portion 255 of the S-shaped membercomprises an adjustable stop and is disposed in the path ofvalve-opening movement of the upturned end of the armature 221 to beengaged thereby and thus limit upward movement of the armature and limitthe extent of opening of the valve 251. The center cross member 21! ofthe S-shaped member 251 has threadedopening therein which is engaged byan adjusting screw 213, so that upon rotation of the screw 213 theSeshaped member 251 will be moved up or down, K

depending on the direction of rotation, to provide for greater or lesseropening movement of the armature 221 and, hence, greater orlesseropening movement of the valve 251.

The lower end or the adjusting screw 213 is rigidly xed to a shait 215rotatable in an opening in the lower housing member |13, and the shaftis provided with an integral knob 211.

In order to give a visual indication of the setting of the adjustablestop 255 and, hence, of the short-time-delay setting, there is provideda pointer 215 (Fig. 5). The pointer is U-shaped and the two legs (onlyone being shown) thereof straddle the adjusting screw 213 and engage innotches 25| (only one being shown) on opposite sides-oi the adjustablestop member 251. The pointer 215 is biased downwardly by means of aspring 253 and has a reduced portion 2235 extending through a slot 281in the scale plate 245 to indicate the setting of the adjustable stop259 and, therefore,the amount of time delay provided for theshort-time-delay operation.

The valve 201 isadjustable to determine the amount of long time delayprovided in the operation of the trip device by means or an adjustableS-shaped stop member 235 (Fig. 6). The stop member 285 is provided witha horizontally disposed stop 29| which is biiurcated to embrace thevalve member 251. A collar .293 on the valve member 251 rests on top ofthe member 29| to determine the amount of opening of the valve 255- 2Iland, therefora'the amount of long time dem lay. A cross member 295 on.the stop member 289 is provided with a threaded opening which isengaged by an adjusting screw 251 having a shaft 292) at its lower endrotatable in an opening in the housing member 113. The shaft 259 has xedthereto a manual knob Sill for rotating the screw 251 and thereby movesthe adjustable stop member up or down depending on the direction of ro*-tation of the screw. Movement of the adjustable stop varies the openingor" the valve 265-2 I I and thereby varies the amount oi longtime delay.

The .long-time-delay adjusting device is provided with a pointer 353similar to the pointer 219 (Fig. 5) for the short-time-delay adjustment.The pointer 353 is U-shaped and straddles the adjusting screw 251 andthe S-shaped stop member 289. The two legs (only one being shown) or"the pointer engage in notches 555 in opposite sides of the stop memberand pivotally engage a shoulder 551 on the housing member I1I. Thepointer 353 is biased downwardly by a spring 359 and has a reducedportion 5I I projecting through a slot EIS in the scale plate 2ll5 toindicate the setting of the long-,time-delay device.

An adjustment is provided for varying the longtime-delay pick-up point,that is, thevminimum overload current required to actuate the mainarmature I53. This adjustment comprises a member @I5 (Figs. 3 and 4)having one end biurcated and the legs 3|1 thereoi pivotally supported inopenings tig (Fig. 3) of the housing member I1I. Theright-hand end ofthe member 3I5 is U-shaped and has opposed inwardlyrextendingprojections 321 engaging an annular groove 323 in the lower portion 51of the armature i555. The projections 32| are biased by means of aspring 325 against the lower wall or" the groove 523, thus biasing thearmature against attraction. The spring 325 has one end hooked into anopening in the member SI5 and the other end attached to an adjustablemember 321 threadedly engaging an adjusting screw 329. The adjustingscrew 329 is secured to a shaft BSI rotatably supported in the housingmember I13 and having a manual knob 553 secured thereto bearing againstthe bottom of the housing member 13. rlhe adjustable member 521 isprovided with a reduced portion 335 extending through a slot 331 in thescale plate 245 to indicate the setting of the long-time-delay pick-up.Botationof the screw 329 will move the member 321 up or down dependingon the direction oi rotation and accordingly vary the tension oi thespring 525 and, hence, the pick-up point of the long-time-delay means.The scale plate 2d5 bears indicia adjacent the several pointers, asshown in Fig. '1, to indicate the settings of the several adjustments ofthe trip device.

The trip device functions with time delays of diierent duration in twodistinct ranges of overcurrents below a predetermined magnitude andinstantaneously in response to overcurrents above the predeterminedmagnitude, or in response to short circuit currents. The ranges or"overcurrents may be arbitrarily defined as, for example, a low range upto 500% or 600% ci normal rated current, an intermediate range between500% or 600% and 1000% of normal rated current, and instantaneous 1000%or more or" normal rated current.

Assuming an overcurrent within the low range ci overcurrents, the tripdevice, with particular reference to Fig. 8, will operate as follows:Upon the occurrence of an overcurrent in the low range of overcurrents,the electromagnet becomes energized and attracts the armature |53upwardly. The armature acts through the spring E53 and the collar |59 toproduce an upward thrust on the trip rod lei, the movement of the tripred being retarded by the partial vacuum below the diaphragm or movableabutment lill. The initial upward movement of the trip rod causes thevalve facing |89 to engage the valve seat |82 on the clamp member 19 tothereby completely seal oli the spaces above and below the diaphragm|61.

The trip rod itl moves slowly upwardly in tripping direction as air isdrawn into the space below the diaphragm through the valve 203-22 untilthe upper end of the trip rod engages the headed screw 99 (Fig. l) andactuates the latch mechanism to eiect tripping of the breaker in thepreviously described manner. The time delay provided by thelong-tirne-delay setting of the valve Zilli-2H is in the order oiseconds and may be varied by adjusting the valve 2te-2H as previouslyset forth.

As soon as the breaker contacts are opened, the tripping magnet |53 isdeenergized and the armature |53. and the trip rod l! are restored bythe spring 325 and the force of gravity to their Fig. 3 positions.Immediately upon deenergization of the tripping magnet H3, the armatureS53 drops into engagement with the upper iace of the clamp member |19.The lower end of the tubular lower portion I5? of the armature member|53 also engages the sleeve |85 and opens the valve Ess- |82 permittinghigh-speed equalization of air pressure above and below the diaphragmit? through the opening |96 in the clamp member ils and through openings33S in the lower of the armature member I5? to thereby eiect high-speedreturn of the parts to their normal lower positions as shown in Fig. 3.

'Upon the occurrence of an overcurrent in the intermediate range ofover-currents, the electromagnet i |53 is energized sufficiently toattract the shcrt-time-delay armature 221 (Figs. and 5) upwardly againstthe adjustable stop opening the valve 28g-2H (Fig. G) an amountdetermined by the adjustment of the stop 2st. This admits air to thespace below the diaill at a higher rate and provides a relatively shorttime delay in the order of altenating-current cycles in the operation ofthe trip rod.

Energization of the tripping magnet i E3 in response to overcurrents inthe intermediate range is not sufficient to attract the armature 225;however, upon the occurrence of an overcurrent of l090% or more of ratedcurrent or a short circuit current, both the sliort-time-delay armaYture Eil and the instantaneous armature 22 are attracted upwardly andmove the valve member to its full extent, thus fully opening the valve2fle-2i i thereby admitting air to the space below the diaphragm itl atarate to permit subnfl Ol) l0 stantially instantaneous tripping movementof the trip rod |6|.

On short-time-delay and instantaneous tripping operations, the spring|63 limits the force applied by the moving armature i 53 to thetimedelay device. On such operations the armature |53 is attracted`immediately against the Xed core member i 2e comprising the spring i53which thus supplies the force necessary to actuate the trip rod 56| thepull exerted on the timedelay device is limited to the maximum forceexerted by the spring |63 when it is compressed. This prevents damage tothe time-delay device and provides a uniform pull on the time-delaydevice.

The circuit breaker is well adapted for the protection oi distributionsystems. Such systems are usually protected by a series of breakersincluding generator breakers, bus tie-in breakers, feeder breakers andload breakers. The circuit breakers of such systems are usually adjustedfor selective tripping; that is, if a fault should occur' at any pointin the system, the breaker nearest the fault and on the generator sideor" the fault should open to clear the fault condition.

The time-current requirement ci the tripping device varies with theposition of the breaker in the selective system for which reason a tripdevice providing a wide range of adjustment is essential. As shown in 9,the trip device is capable of a wide range or" adjustments. There ilveseparate adjusting devices ll located outside the device for ease oi"accessibility. By way of example of the ran 'es of adjustments, thefollowing have been arbitrarily selected as illustrative ci' ranges ofadjustments:

l. Range of long-time-delay pick-up, from to 160% of coil rating.

2. Range of long time delay, from 23 to 85 seconds.

Range of short-time-delay pick-up 509% te 10005727 of coil rating.

e. Range of short time delay, from fi to 30 alternating-current cycles.

5. Range of instantaneous .000% to 1.500% of coil rating.

9 graphically illustrates the ranges of the everal adjustments of thetrip device. Along the left-hand edge of S is indicated the time inseconds. The percentage oi coil rating is shown along the bottom, andthe time in alternating-current cycles based on Sil-cycle frequency isshown along the right-hand edge of Fig. 9. Curve A represents theminimum settings and curve B, the maximum settings. By adjusting thesnob (Figs. 3, and 8) the long-timedelay pick-up may be adjusted topiel: up at any point in the band of adjustments defined by curves .ft-Bas at C, that is, for example, between 80% and 160% of coil rating.Adjusting the knob 35| (Figs. d, 7 and 8) which controls the initialopening of the valve 26d-2| i varies the amount of long delay between 23and 8S seconds as indicated at D in Fig. 9. As indicated at E (Fig. 9)the short-ti.` e-delay pick-up may be set to piclc between 500% and cicoil rating. This is effected by adjusting the knob '255 (Figs 7 8).amount of short time delay may' be varied between 4 and 30 cycles, asindicated at l, by adjusting the knob 2li (Figs. 5, 'Z and SL Finallythe instantaneois pick-up point may be varied between 30111074, 150075of coil rating, as indicated at Cr in Fig. 3 by adjusting the knob 242i(Figs-U from pirfi-up, from Til and 8 which controls the tension ofthebiasing .for t e instantaneous armature 229. ci these adjustments may beeasily made by merely turning the adjusting linob associated with.particular adjusting device previously described. The adiustments areindependent of each other and, as shown in Fig. '7, all of the adjustingirnobs are conveniently located.

The complete adjustability of trip device eliminates the necessity ofincreasing band Width of adjustments to compensate for manufacturingvariations different coil ratings. |'She variations of tripping time dueto temperature changes is negligible. This is made possible by the useci air as the delaying medium. ri`he tripping tz' depends on thevelocity of air flow through the valve oriiice and is not affected bychanges inair density.

{ai/'ing described the invention in accordance with the patent statutes,it is to be understood that various changes modifications may be made inthe structural details and combination of elements disclosed Withoutdeparting from some oi the essential features of the invention.

W claim as our invention:

1. En an electromagnetic trip device including a trip rod movable toeffect a tripping operation, said trip device comprising an energizingWinding, an armature operable upon energization of said winding to movesaid trip rod, a time-delay element for retarding tripping movement ofsaid trip rod having a chamber, a normally open valve for admitting nuidto said chamber at a predetermined rate to eiect a relatively long timedelay in the tripping movement of said trip rod, and a second armatureoperable by energicationY of said Winding in response to cetain abnormalcircuit conditions to actuate said valve and increase the rate of'admission of fluid to said chamber to eiiect a relatively short timedelay in the tripping movement of said trip rod.

2. In a circuit breaker having relatively movable contact means andoperating means therefor, the combination of a trip member operable toeect a tripping operation, an electromagnetic trip device comprising anenergizing Winding, an armature operable upon energization of saidwinding in response to overload currents to operate said trip member, atime-delay element for retarding tripping operation of said trip memberhaving a chamber, a valve having an initial open position for admittingfluid to said chamber at a predetermined rate to effect a relativelylong time delay in the tripping` operation or said trip member, avalve-operating armature operable upon energization of said Winding inresponse to predetermined abnormal circuit conditions to actuate saidvalve and increase the rate oi admission of iiuid to said chamber toeffect a relatively short time delay in the operation of said tripmember, and adjusting means for adjusting the initial open position oisaid valve to vary the amount of time delay provided by said initialopen position of said valve.

3. ln a circuit breaker having relatively movable contact means andoperating means therefor, the combination of a trip member operable toeffect a tripping operation, an electromagnetic trip device comprisingan energizing winding, an armature operable upon. energization or saidwinding in response to overload currents to opcrate said trip member, atime-delay element for retarding tripping operation of said trip memberhaving a chamber, a valve having an initial open position for admittingfluid to said chamber ata predetermined ratev to4 effect arelativelylong timedelay in the tripping operation ofV said trip member,a valve-operating amature operable upon energization of said winding inresponse to predetermined abnormal circuit conditions to actuate saidvalve and increase the rate of admission of iiuid to' said chamber toeiTect a relatively short time delay in the operation of said tripmember, and adjusting means for adjusting the initial open position ofsaid valve to vary the amount of time delay provided by said initialopen position oi said valve, an adjustable stop for limiting the openingmovement of said valve-operating armature, and adjusting. means forvarying the setting of said adjustable stop to vary the extent or"opening of. said valve and the amount oi said short time delay;

4. In-a circuitY breaker having relatively mov"- able contacts andoperating means therefor, the

combination of a trip rod, an electromagnetic trip device comprising anenergizing Winding, an armature operable upon encrgiaation of saidWinding in response to overload currents to operate said trip rod, atime-delay element for. retarding tripping operation oi said trip rodincluding a chamber, a valve having,` an initial open position foradmitting fluid to said chamber at a predetermined rate to eiect arelatively long time delay in the operation of said trip rod, a firstvalve-operating'armature operable upon energization of said winding inresponse to overload currents below a predetermined value to actuatesaid valve' to predetermined distance in opening direction to increasethe rate of admission of fluid to said chamber to thereby effect arelatively short time. delay inthe operation ci said trip rod, and asecond valve-operating armature operable upon energiaation or saidWinding in response' to overload currents above said predetermined valueto actuate said valve to the full open position and permit instantaneousoperation of said triprod.

5. In: an electromagnetic trip device comprising a trip member, anenergizing winding, an armature operable lupon energication of saidWinding to actuate rip member, a timedelay element comprising a movableabutment for retarding tripping movement oi said trip member, meansdenning a chamber, a valve for admitting iuid to said chamber, a firstvalveoperating armature operable upon energization of said Winding inresponse to overload currents below a predetermined value to open saidvalve a predetermined distance to admit fluid to said chamber at apredetermined rate to retard tripping movement of said trip member, anda second valve-operating armature operable upon energization of saidWinding in response to overload currents above said predetermined valueto actuate said valve to theA full open position to permit instantaneousoperation of said trip member.

6. In an electromagnetic trip device comprising a trip member, anenergizing Winding, an armature operable upon energization of saidwinding to actuate said trip member, a timedelay element comprising amovable abutment for retarding tripping movement of said trip member,means defining a chamber, a valve for admitting fluid to said chamber, afirst valveoperatingv armature operable upon energization of saidwinding in response to overload currents below a predetermined value toope-n said valve a predetermined distance to admit fluid to said chamberat a predetermined rate .to retard tripping movement of said tripmember, and a second valve-operating armature operable uponenergia/ation of said winding in Vresponse to overload currents abovesaid predetermined value to actuate said valve to the full open positionto permit instantaneous operation of said trip member, and adjustablemeans for varying'the amount of opening of said valve bysaid firstvalve-oper.- ating armature to vary theamount of time delay.

7. ln an electromagnetic trip device comprising a trip member, .anenergizing winding, an armature operable upon .energization of saidwinding in response to overloadV currents to actuate said trip member, atime-delay device comprising a uid; daslipot for retarding trippingmovement of said trip member, asingle value' controlling a passage foradmittinguid to's'aid daslipot, a pair'of valve-operating armatures foractuating said valve in opening direction to admit fluid to said dashpotto permit tripping movement of Asaid trip member, means limiting themovement 'of one of said armatures'to thereby limit the amount ofopening of said valve When said valve is operated by said one armatureto provide a time delay in the tripping movement of said trip member.

8. In an electromagnetic trip device comprising a trip member, anenergizing Winding, an armature operable upon energization of saidwinding in response to overload currents to aetuate said trip member, atime-delay device comprising a fluid dashpot for retarding trippingmovement of vsaid trip member, a. single valve controlling apassage foradmitting uid to said dashpot, a pair or" valve-operating armatures foractuating said valve in opening` direction to admit iiuid to saiddashpot to permitrtripping movement of saidtrip member, means limitingthe inovement'ofone of said armatures to thereby limit the amount ofopening of said valve when said valve is operated by said one armatureto provide a time delay in the tripping movement-of said trip member,and adjusting means for varyingthe amount of opening of said valve bysaid one armature to thereby vary the amount of time delay.

9. In an electromagnetic trip device comprising a trip member, anenergizing Winding, an armature operable upon energization of saidWinding in response to overload currents to operate said trip member, atime-delay device com*- prising a fluid dashpot for retarding trippingmovement of said trip member, a single valve controlling a. passage foradmitting fluid to said daslipot, said valve having a normal partiallyopen position for admitting fluid to said dashpot at a predeterminedrate to eiiect a relatively long time delay in tne tripping operation ofsaid trip member, a rst armature operable when said Winding isenergizedin response to-overload currents below a predetermined value toactuate said valve to an intermediate open position to increase the flowof uid to said dashpot and thereby eect a relatively snort time delay inthe operation of said trip member, and a second armature operable saidWinding is energized in response to overload currents above saidpredetermined value to actuate said valve to a full open position topermit instantaneous operation of said trip member.

l0. in an electromagnetic trip device compris ing a trip member, anenergi ing winding, an armature operable upon energization of saidwinding in response to overload curi-entete operate said tripmember, atime-delay device comprising a fluid daslipot for retarding trippingmovement of said trip member, a single valve controlling a passage foradmitting to said daslipot, said vave having a normal partially openposition for ad; tting to said dashpot at a predetermined rate to effecta relatively long time delay in the trippmg o eration of said tripmember, a iirst armature ie when said winding is energized in responseto overload currents belov.7 a predetermined value to actuate said valveto an intcrr colate open position to increase the new oi uid to saiddaslipot and thereby effect a relatively snort time deiay in theoperation of said trip member, and a second armature operable when swinding energized in response to overload currents above predeterminedvalue to actuate ve to a full open position to permit instany of saidtrip member, means for selectiveli7 ely mova- A pans the ein a partiallyo tion to admit fiuid to said daslipo'- determined rate to effect a longti" the order or seconds in the oper trip means, a rsty armature eperabelectroresponsive means is energ to overload currents below a pred toaetuate said valve and cause sani t v crease the rate of admission ofiiuid to s pot to effect a short time delai" in the order ofalternating-current cycles in the operation of said trip means, and asecond armature operable When said electroresponsive .e s is energizedin response to overload currents e tov-e predetermined value to aetuatesa re to full or position to admit iuid to said daslipot rate to permitinstantaneous operation of trip means.

l2. In a circuit breaker leavin@ rela tire-1y movi.- ble contact meansand opereL therefor, the combination of t i sponsive means for operatmtime-deiaj; means comprising a retarding tripping operation of sa avalve having an initial oper pos erable to intermediate and full opeadmit fluid to said daslipeL means for tably detei ing opening of sarlvalve in said mediate position, ld valve in position admitting .Quid tosaid determined rate eieet a rele' delay in the operation of armatureoperable when said means is ener ired respon rents below a pret saidvalve to said interni increase the rate of dashpot to thereby ei'ectrelativeiy delay in the operation of said trip ond armature operablewhen s'f 'roresponsive moans is energized in r Y overload currents abovesaid predeternnneov Yalue to operate said valve to the iuil openposition te admit cue '15 iluid-to said dashpot ata rateto permitinstantaneous operation of said trip means, andseparate adjusting meansJfor said first and second armatures for selectively determining theminimum overload currents required to actuate said armatures.

13. In a circuit breaker having relatively movable contact means andoperating means therefor, the combination or trip means,electroresponsive means for operating said trip means, time-delay meanscomprising a fluid dashpot or retarding tripping operation of said tripmeans, a valve operable to an intermediate position and to a full openposition to admit to said dashpot, av first armature operable when saideleotroresponsive means is energized in response to overload en rentsbeloiv a predetermined value to operate said valve to said intermediateposition to admit fluid to said dashpot at a rate to effect a time delayin the operation oi said trip means, and a second armature operable Whensaidelectroresponsive means is energized in respenseY to overloadcurrents abovev said predetermined value to operate said valve to fullopen position to admit fluid to said dasnpot at a rate to' permitinstantaneous operation of said trip means.

14. In a circuit breaker having relatively movable contact means andoperating means therefor, the combination of trip means,electroresponsive means for operating said trip means, time-delay meanscomprising a iluid dashpot for retarding tripping operation of said tripmeans, a valve operable to an intermediate position and to a full openposition to admit uid to said dashpot, a' first armature operable Whensaid electroresponsive means is energized in response to overloadcurrents below a predetermined value to operate said valve to saidintermediate position to admit fluid to said daslipot at a rate toeffect a time delay inthe operation of said trip means, and a secondarmature operable when said eleotroresponsivc means is energized inresponse to overload currents above said predetermined value to operatesaid valve t full open position to admit duid to said dashpot at a rateto permit instantaneous operation of said trip means, separa-te biasingmeans biasing said armatures against opera-tion, and separate adjustingmeans for varying the bias of said biasing means to vary the minimumoverload currents required to operate said armatures.

15. In a circuit breaker having relatively'movable .contact means andoperating means therefor, tbe combination of trip means,electroresponsive means for operating said trip means, time-delay meanscomprising a fluid dashpot for retarding tripping operation of said tripmeans, a valve operable to an intermediate position and to a full openposition to admit iiuid to said dashpot, a pivot armature operable whensaid electroresponsive means is energized in response to overloadcurrents below a predetermined value to operate said valve to saidintermediate position to admit fluid to said dashpot at a rate to effecta time delay in the operation of said trip means, adjustable means forselectively determining the extent of opening of said valve by saidfirst armature to vary the amount of time delay, and a second armatureoperable when said electroresponsive means is energized in response tooverload currents above said predetermined value to operate said valveto full open position to admit fluid to said dashpot at 9.- rate toper-v mit instantaneous operation of said tripk means.

16. In an electromagnetic trip, device com'- prising a: trip, rod, amain armature movable to actuate said trip rod, time-delay means forkretarding tripping movement of said trip rod comprising a iluid dashpotconnected to said trip rod, a single valve openable to admit fluid tosaid dashpot at diierent rates, and a plurality of valve-operatingarmatures operable upon energizationv of said electromagnetic means inresponse to overload currents o different magnitudes to open said valvediierent extents.

1'?. In an electromagnetic trip device comprising a trip rod, a mainarmature movable to actuate said trip rod, time-delay means forretarding tripping movementof said trip rod comprising a fluid dashpotconnected to said trip rod, a single valve openable to admit fluid tosaid dashpot at diierent rates, and a plurality of valve-operatingarmatures operable upon energization of said electromagnetic means inrespense to overload currents or different magnitudes to open4 saidvalve diierent extents, and adjustable means for varying the extent ofopening movement or one of said armatures.

18. In an electromagnetic trip device comprising a trip rod, a mainarmature movable to actuate said trip rod, time-delay means forretarding tripping movement of said trip rod comprising a fluid dashpotconnected to said trip rod, a single valve openable to admit fluid tosaid dashpot at different rates, and a plurality of valve-operatingarmatures operable upon energize-tion of said electromagnetic means inresponse to `overload currents or different magnitudes to open saidvalve diierent extents, separate biasing means for said main armatureand each oi said valve operating armaturesy and a separate adjustingdevice for adjusting each of said biasing means to vary the minimumoverload current required to operate said main armature and eaclrof saidvalve-operating armatures.

19. In a circuit breaker having relatively movable contact means andoperating means therefor, the combination of a trip member,electromagnetic means for operating said trip member, a time-delaydevice for retarding operation of said trip member, a single controlelement for said time-delay device, said control element having a irstposition in which said control element controls said time-delay deviceto eil-ect a relativelyr long time delay in the operation of said tripmember, adjusting means for adjusting the first'position of said controlelement to vary the amount of time delay provide by said timedelaydevice in the iirst position of said control element, biasing means forsaid electromagnetic means, adjusting means for adjusting said biasingmeans to vary the minimum overload current required to operate said tripmember, a first electroresponsi've means responsive to overload currentsbelow a predetermined value to move said control element to a secondposition to effect a relatively short time delay in the operation ofsaid trip member, adjusting means for adjusting said. second position ofsaid control element to vary the amount oi time delay rovided by saidtime-delay device when said control element is in said second position,biasing means biasing said first electroresponsive means againstoperation, adjusting means for adjusting said biasing means to vary theminimum overload current required to operate said firstelectroresponsive means to move said control element to said secondposition, a second electroresponsive means responsive 17 to overloadcurrents above said predetermined value to move said control element toa third position to effect instantaneous operation of said trip member,biasing means biasing said second electroresponsive means againstoperation, and adjusting. means for adjusting said biasing means to varythe minimum overload current required to operate said secondeiectroresponsive means and move said :control element to said thirdposition.

JOHN B. MACNEILL. HARRY J. LINGAL.

References cited in the me of this patent Number UNITED STATES PATENTSName Date Wilhelm May 16, 1939 Lindstrom et a1. Oct. 19, 1948 GravesNov. 1, 1949 Jensen Feb. 27, 1951

